KR101270403B1 - Hybrid complexly contaminated soil washing system and method by ultrasonic oxidation-extraction - Google Patents

Abstract

PURPOSE: An ultrasound oxidation hybrid soil purification system and a method are provided to reduce the amount of usage of an oxidant as an ultrasound to reduce the secondary pollution caused by the usage of chemicals and reduce the amount of sludge treatment by letting the fine earth and sand rising separate by bubble. CONSTITUTION: An ultrasound oxidation hybrid soil purification system comprises a selecting apparatus(110); an ultrasound oxidation washing tub(120); an after selecting apparatus(130); and a floating device(140). The selecting apparatus distributes the soil into droplet sizes from the excavated and polluted soil. The ultrasound oxidation washing tub washes the distributed soil crop using the ultrasound and oxidant. The after selecting apparatus distributes the washed soil into droplet sizes. The floating apparatus separates the fine earth and sand from the soil flowed from the after selecting apparatus with bubble.

Description

Hybrid complexly contaminated soil washing system and method by ultrasonic oxidation-extraction

The present invention relates to an ultrasonic oxidation-extraction hybrid complex contaminated soil purification system and method, which will be described in more detail, which is suitable for the purification of complex contaminated soil contaminated with oil and heavy metals by hybridizing ultrasonic oxidation and bubble solid-liquid separation. An ultrasonic oxidation-extract hybrid hybrid contaminated soil purification system and method that can reduce sludge throughput by allowing to classify soils.

In recent years, the importance of the soil environment, which is affected by development projects due to heightened soil and groundwater pollution due to waste and toxic chemicals generated by population growth and industrial development, is emerging.

Especially, as the economic development and the income level have improved, the oil usage due to the supply of automobiles has greatly increased along with industrial activities. Accordingly, pollution of soil and groundwater due to leakage of oil and harmful chemicals classified as non-aqueous liquid (NAPLs) in oil storage tanks of petrol stations and underground storage tanks of industrial facilities storing chemical substances are highlighted.

In addition, as a factor of soil pollution, heavy metals include lead, arsenic cadmium with positive charge and arsenic with negative charge. Since the problem of heavy metal contaminated soil in waste mines and industrial complexes has been raised since 2000, the purification of heavy metal contaminated soil has been highlighted as a new field. Soils contaminated with heavy metals have no odor or color change and can not be visually confirmed. Most of the contaminated soil remediation projects in Korea are conducted mainly on oil contaminated soil, and only a few of the heavy metal contaminated soil remediation projects are carried out.

On the other hand, when examining the specificity and pollution characteristics of industrial complexes caused by landfilled waste among complex polluted lands, industrial complexes built by landfill by national and local governments have been established in accordance with the Law on the Promotion of Waste Recycling under the Waste Management Act before the Soil Environment Conservation Act was revised. The waste gypsum is recycled as a cover material, and landfilled on industrial complex sites or wastes that have been illegally buried for a long time have negative ions such as oil pollutants, complex heavy metal contaminants such as zinc, nickel, lead, and copper, fluorine, and arsenic. Contaminants are investigated for a variety of causes. In particular, the industrial complexes that are recycled by recycling the waste are diversified by the factories that are using the sites to produce them. Therefore, it is very difficult to identify and identify the causes of the industrial pollution caused by the existing landfilled waste and industrial activities have.

In this regard, Korean Patent Registration No. 10-0903593 discloses a dry sorting step for separating particles from contaminated soil, a washing step for putting contaminated soil from which particles are separated into a washing tank through an input hopper, and putting the washed soil into an ultrasonic washing tank. It proposes a technique including the step of washing using ultrasonic energy.

However, in the case of the above technique, it is possible to purify complex contaminated soil contaminated with oil and heavy metal by using ultrasonic waves, but to classify the soil according to particle size by repetition of vibration separation, etc. There is a problem that the sludge throughput increases due to insufficient classification.

Meanwhile, Korean Patent Registration No. 10-0988047 discloses a stirring step of adding and mixing a mixed detergent to contaminated soil, a classification and washing step of separating soil particles while washing the stirred contaminated soil, and separating soil particles having a large particle size from the soil. A technique including a particulate solid-liquid separation step is proposed.

However, in the case of the above technique, by simply adding a mixed washing agent to clean the contaminated soil, a sufficient purification efficiency cannot be expected for the complex contaminated soil, and the hydrocyclone is proposed by the technique proposed in the solid-liquid separation step. Even in the case of the hydrocyclone, there is still a problem in that the sludge throughput is increased because it cannot classify the fine soil.

Republic of Korea Patent Registration No. 10-0903593 Republic of Korea Patent Registration No. 10-0988047

An object of the present invention is to provide a hybrid soil purification system and method capable of simultaneously treating oil and heavy metals, which can be applied to complex soil, and at the same time, can classify fine soil and reduce sludge throughput.

Ultrasonic oxidation-extract hybrid hybrid soil contamination purification system of the present invention as a means for achieving the above object, the sorting device for classifying the soil by the particle diameter in the excavated contaminated soil; Ultrasonic oxidation cleaning tank for cleaning by using an ultrasonic wave and an oxidizing agent classified in the soil contaminated from the sorting device; A post-screening device for classifying the soil washed in the ultrasonic oxidation tank by particle diameter; Characterized in that it comprises a; floating device for separating the solid-liquid by the bubble from the earth and sand introduced from the rear-screen sorting device.

That is, the present invention is to purify the complex soil contaminated with oil and heavy metals by ultrasonic oxidation at the ex-situ, and to classify the fine soil by the flotation of the fine soil by the bubble after washing to reduce the amount of sludge generated. A hybridized soil purification system that can be reduced.

Here, the rear sorting device includes a hydrocyclone for discharging soil having a large particle size, and a sedimentation tank for precipitating small soil with a particle size classified from the hydrocyclone, so that the washed soil is classified by particle size.

In addition, in the present invention, the flocculated sedimentation tank for precipitating the solid-liquid separation of the solid-liquid separation from the flotation device to react with the flocculant is included so as to treat the sludge-ized fine soil.

Meanwhile, in the present invention, an example of the floating device is provided. The floating device includes an inlet on one side and an outlet on the other side, and a lower side of the floating tank on which a slope is formed, and a lower portion of the floating tank. The diffuser is formed with a diffuser nozzle, and the sludge strainer is formed in the mesh form on top of the floating tank.

More preferably, the injection nozzle is composed of an injection tube having a plurality of discharge holes formed thereon, and a hemispherical diffuser formed with a plurality of acid pores formed at an upper end of the injection tube so that the microbubble floats over a large area in the floating tank. It is reasonable to make it possible.

On the other hand, the ultrasonic oxidation-extraction hybrid composite contaminated soil purification method of the present invention, the screening step of classifying the soil by particle diameter in the excavated contaminated soil; An ultrasonic oxidation step of cleaning the classified soil using ultrasonic waves and an oxidizing agent; A post-screening step of classifying the washed soil by particle diameter; Floating solid separation step of classifying the fine soil by the bubble; Characterized in that it comprises a; after the treatment step of treating the sludge.

Ultrasonic oxidation-extraction hybrid composite contaminated soil purification system and method of the present invention can remove oil and heavy metals by ultrasonic oxidation, which is advantageous for the purification of complex contaminated soil.

In addition, the ultrasonic oxidation-extract hybrid hybrid contaminated soil purification system and method can reduce the amount of oxidant used by using ultrasonic waves, thereby reducing the secondary pollution by the use of chemicals.

In addition, the ultrasonic oxidation-extract hybrid hybrid contaminated soil purification system and method enables the flotation and separation of fine soil, which was not easy to classify in existing systems and methods, to increase secondary pollution and cost due to excessive sludge. There is an advantage to prevent.

1 is a schematic diagram showing an ultrasonic oxidation-extraction hybrid composite soil cleaning system of the present invention,
Figure 2 is a perspective view showing an example of the ultrasonic oxidation-extraction hybrid complex soil purification system of the present invention,
Figure 3 is a schematic diagram showing an embodiment of the flotation device which is one component of the ultrasonic oxidation-extraction hybrid complex soil cleaning system of the present invention,
Figure 4 is a block diagram showing the ultrasonic oxidation-extraction hybrid composite contaminated soil purification method of the present invention.

Hereinafter, the structure and operation of the present invention will be described in more detail with reference to the accompanying drawings. In describing the present invention, the term or word used in the present specification and claims is based on the principle that the inventor can appropriately define the concept of the term in order to best describe the invention of his or her own. It should be interpreted as meanings and concepts corresponding to the technical idea of

1 is a schematic diagram showing an ultrasonic oxidation-extraction hybrid complex soil contamination purification system of the present invention, Figure 2 is a perspective view showing an example of the ultrasonic oxidation-extraction hybrid complex soil contamination purification system of the present invention, Figure 3 is Figure 4 is a schematic diagram showing an embodiment of a flotation device that is one component of the ultrasonic oxidation-extraction hybrid complex soil cleaning system, Figure 4 is a block diagram showing the ultrasonic oxidation-extraction hybrid complex soil contamination purification method of the present invention.

Ultrasonic oxidation-extraction hybrid composite contaminated soil purification system of the present invention, the sorting device 110 for classifying the soil by particle diameter in the excavated contaminated soil as shown in Figure 1; Ultrasonic oxidation cleaning tank 120 for cleaning by using the ultrasonic and oxidizing agent in the soil contaminated classified from the sorting device 110; A back screening device (130) for classifying the soil washed in the ultrasonic oxidation tank by particle diameter; Floating device 140 for separating the solid-liquid by the bubble from the earth and sand introduced from the rear screening device 140; And a flocculation sedimentation tank 150.

The sorting device 110 is to sort the particles having a large particle size by dry in contaminated soil such as gravel, garbage, such sorting device 110 does not limit the kind of screen or the like. In general, the soil is contaminated with less than 0.2mm in the contaminated soil to flow to the ultrasonic oxidation cleaning tank 120.

The contaminated soil in which the particles are primarily selected is allowed to flow to the ultrasonic oxidation cleaning tank 120 so that oil and heavy metals are separated by ultrasonic waves and oxidizing agents. In the ultrasonic oxidizing washing tank 120, the washing water, the oxidizing agent, and the polluted soil selected first are mixed, and the washing process of oil and heavy metal is performed by ultrasonic waves.

The ultrasonic process in the ultrasonic oxidation cleaning tank 120 is a process using ultrasonic waves (> 18 kHz) higher than the human audio frequency. When ultrasonic waves are irradiated to a liquid while repeating compression / expansion, the liquid intermolecular distance is narrowed and widened. When the intermolecular distance is larger than a distance capable of maintaining the liquid, a cavity, ie, air bubbles, is formed. The cavity is to serve to concentrate the energy of the ultrasonic waves in the bubble, when the bubble is formed so that the high temperature and high pressure is generated to be able to decompose the compound. In addition, heavy metal desorption may be promoted by the shock wave generated when the bubbles formed by the ultrasonic waves collapse. Therefore, the ultrasonic wave can greatly contribute to the removal of organic matters such as heavy volatile oils and the desorption efficiency of heavy metals, and is suitable for the purification of complex contaminated soil contaminated with volatile oils and heavy metals.

In addition, OH radicals are generated in an aqueous solution containing contaminated soil due to the application of ultrasonic waves, thereby oxidatively decomposing heavy volatile oils, and when used in combination with other oxidizing agents, promotes the generation of OH radicals or regenerates other oxidizing agents. The efficiency is improved and the amount of oxidant injected can be reduced. By applying ultrasonic waves, it is possible to reduce the amount of oxidant injection, thereby preventing secondary contamination by the use of excess oxidant.

The oxidant is not limited to the kind thereof, and ozone, titanium dioxide, iron, and the like may be used.

The earth and sand washed in the ultrasonic oxidation cleaning tank 120 flows to the rear screening device 130, and the rear screening device 130 classifies and discharges the earth and sand including fine earth, and the rear screening device. Soil discharged through the earth and sand discharge line 131 configured in 130 to be discharged.

As shown in FIG. 1, the rear-screening device 130 includes a hydrocyclone 132, which is connected to the sedimentation tank 133.

The solution containing the earth and sand separated from the oil and heavy metals in the ultrasonic oxidation washing tank 120 flows to the hydrocyclone 132 to discharge the earth and sand exceeding a predetermined particle size based on the rotational force, the hydrocyclone ( 132 is a well-known technique, and a detailed description thereof will be omitted. In addition, although not shown in the drawing in connection with the hydrocyclone 132, it is possible to further improve the classification efficiency of the fine soil by the multi-hydrocyclone is further configured. In the case of such hydrocyclones 132, it is possible to discharge the earth and sand selected to be approximately 0.075mm or more, and when the multi-hydrocyclone is added to discharge the earth and sand selected to 0.02mm or more, less than 0.02mm fine earth and sand In case of non-classification, the use of hydrocyclone 132 (multi-hydrocyclone) alone is an uneconomical increase in sludge throughput. Accordingly, the present invention is to present a flotation device 140 to be described below.

In addition, the sedimentation tank 133 as the rear sorting device 130 corresponds to a configuration for inducing the deposition of fine soil while storing a solution containing the fine earth soil classified in the hydrocyclone 132. However, in the case of the sedimentation tank 133, the induction of deposition is not easy due to the small specific gravity of the fine soil, and the floating device 140 is further presented.

The flotation device 140 is to create a bubble so as to induce the flotation of the fine soil attached to the bubble based on the rise of the bubble to classify the fine soil through the earth and sand discharge line 141, so that the solid by the bubble Separation is possible even in the case of fine soil less than 0.02mm. In other words, the sludge throughput can be reduced as much as the post-treatment, and the purification efficiency can be increased.

Meanwhile, in the present invention, an example of the floating device 140 is shown in FIG. 3, and the floating device 140 includes a floating tank 142 and a diffuser 143 in which a plurality of injection nozzles 144 are formed. And by spraying the bubble through the injection nozzle 144 to the solution containing the fine soil introduced into the flotation tank 142 to allow the fine soil to float in a state attached to the bubble.

The floatation tank 142 is formed with an inlet 142-1 on one side to introduce a solution containing fine soil, and an outlet 142-2 is formed on the other side to externalize the solution in which the fine soil is classified (coagulant precipitation tank). (150)) to be discharged. In addition, the floating tank 142 is formed in the lower portion of the floating tank 142 by depositing soil having a relatively high specific gravity in the solution in which the fine earth sand is classified by the lower surface (142-5) to form a slope gradient. The sedimentary soil is discharged to the outside through the sedimentary soil discharge outlet 142-4. In addition, the upper portion of the floating tank 142 may be configured to discharge the suspended fine soil by forming a overflow pipe (142-3). Floating fine soil may be discharged to the outside through the overflow pipe (142-3), or may be discharged to the outside using other scums, such extraction of the suspended fine soil in various structures (methods) Of course, it can be performed by.

The diffuser 143 is connected to the brower 145 outside the floatation tank 142, and is configured at the lower portion of the floatation tank 142, and the air delivered through the diffuser 143 is transferred to the diffuser. Air is injected through the plurality of injection nozzles 144 formed on the upper portion 143 to form bubbles.

In addition, a sludge filter net 146 is formed at the bottom of the surface as an upper portion of the floating tank 142, the sludge filter net 146 is a mesh 146-1 is configured to prevent the sludge contained in the solution to float. The fine soil is to be suspended through. The reason for constituting the sludge filter net 146 is that the sludge is mixed with the fine soil suspended by floating together with the bubble is to be configured to eliminate this inconvenience because a separate sludge removal process.

3 illustrates an embodiment of the injection nozzle 144, the injection nozzle 144 may include an injection pipe 144-2 having a plurality of discharge holes 144-1 formed therein, and It is composed of a hemispherical diffuser 144-4 in which a plurality of diffuser pores 144-3 are formed at the upper end of the pipe 144-2. Air introduced through the injection pipe 144-2 is discharged to the discharge hole 144-1, and the discharged air is a plurality of acid pores 144-3 formed in the diffuser 144-4. It is to be discharged into the micro bubble through. That is, as the microbubble is formed, the surface area of the generated bubble can be increased to increase the amount of floating of fine soil by that amount. The diffuser 144-4 is formed in a hemispherical shape so that the microbubble can be generated in multiple directions. Therefore, it is to be able to float the fine soil in a large area.

As mentioned above, the solution in which the fine soil is classified by the flotation device 140 is flowed to the flocculation settling tank 150, and the flocculating agent is added to the solution of the flocculation settling tank 150, thus sludge (colloidal property). Contaminated microcetosa).

The sludge precipitated in the flocculation sedimentation tank 150 is not shown in the drawing, but is concentrated in a concentration tank and can be recycled by being caked by a filter press or the like.

Meanwhile, the present invention also provides an ultrasonic oxidation-extraction hybrid complex soil purification method as shown in FIG. 4. Purification method of the present invention, the sorting step of classifying the soil by particle diameter in the excavated contaminated soil (S10); An ultrasonic oxidation step (S20) of washing the classified soil soil using ultrasonic waves and an oxidizing agent; A post-screening step of classifying the washed soil by particle diameter (S30); Floating solid separation step (S40) for classifying the fine soil by the bubble; Characterized in that it comprises a ;; the post-treatment step (S50) for treating the sludge.

110: sorting device 120: ultrasonic oxidation cleaning tank
130: sorting device 140: floating device
150: coagulation sedimentation tank

Claims (7)

A sorting device for classifying soil by particle diameter in the excavated contaminated soil;
Ultrasonic oxidation cleaning tank for cleaning by using an ultrasonic wave and an oxidizing agent classified in the soil contaminated from the sorting device;
A post-screening device for classifying the soil washed in the ultrasonic oxidation tank by particle diameter;
A flotation device for solid-liquid separation of fine soil by bubbles from the soil flow introduced from the rear screening device;
Ultrasonic oxidation hybrid soil purification system characterized in that comprises a.
The method of claim 1,
The rear sorting device,
An ultrasonic oxidation hybrid soil purification system, characterized in that it comprises a hydrocyclone for discharging large-sized soil, and a sedimentation tank for precipitating the small-soil classified from the hydrocyclone.
The method of claim 1,
Ultrasonic oxidation hybrid soil purification system, characterized in that it comprises a flocculation sedimentation tank for precipitating by the flocculant is the solid-liquid separation is completed from the flotation device.
The method of claim 1,
The flotation device,
Ultrasonic oxidation hybrid soil purification system characterized in that the inlet is formed on the inlet and the other side discharge port and the lower surface forming a slope gradient, and the lower portion of the floatation tank is composed of a diffuser formed with a plurality of injection nozzles.
5. The method of claim 4,
Ultrasonic oxidation hybrid soil purification system characterized in that the upper portion of the floating tank is formed of a sludge filter net formed in the mesh form so that the bubble passes through the mesh, the sludge is filtered.
5. The method of claim 4,
The spray nozzle is an ultrasonic oxidation hybrid soil purification system, characterized in that the injection pipe is formed with a plurality of discharge holes formed in the upper portion, and a hemispherical diffuser formed with a plurality of acid pores in the upper end of the injection tube.
A sorting step of classifying soil by particle diameter in the excavated contaminated soil;
An ultrasonic oxidation step of cleaning the classified soil using ultrasonic waves and an oxidizing agent;
A post-screening step of classifying soil by particle diameter in the washed contaminated soil;
Floating solid separation step of classifying the fine soil by the bubble;
A post-treatment step of treating sludge;
Ultrasonic oxidation hybrid soil purification method characterized in that it comprises a.

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